1. Field of the Invention
This invention is concerned with lockable tie down straps.
The invention is concerned particularly although not exclusively with lockable tie down straps to secure sporting equipment such as surfboards, snow boards or the like to vehicle roof racks or similar support structures.
2. Description of the Prior Art
Valuable sporting articles such as surfboards, snow boards, sail boards, kayaks, canoes and the like are usually transported on a vehicle roof rack or a support structure such as sports bars associated with a pick-up truck. Often these sporting articles are left unattended for considerable periods of time leaving the surfboards, snow boards, sail boards, kayaks, canoes or the like vulnerable to theft.
Over the years many anti-theft securing devices have been proposed.
One such device is disclosed in U.S. Pat. No. 6,003,348 relating to a surfboard cable lock having a fixed loop swaged at one end of the cable and a releasable loop at the other end secured to a body member by means of a padlock or the like. While the cable is lockable around the body of the surfboard adjacent the fin or fins to prevent theft of the surfboard, separate tie down straps are required to secure the surfboard to a vehicle roof rack or the like. Where the board has removable fins, this locking system is ineffective.
U.S. Pat. Nos. 5,119,649 and 5127861 and U.S. patent application Ser. No. 10/495,178 all describe locking mechanisms for surfboards which require the formation of through holes through the body of the surfboard or the incorporation into the body of the surfboard of a specially shaped socket member adapted to receive a complementary shaped spigot on the end of a cable to secure the surfboard to a vehicular roof rack. As most surfboards are not manufactured with these fittings they must be retrofitted which is expensive and disfiguring to the surfboard and can comprise the structural integrity thereof. Like the locking cable of U.S. Pat. No. 6,003,348, separate tie down straps are required which adds to both expense and increases the inconvenience of use.
U.S. Pat. Nos. 3,875,771 and 4685315 describe luggage strap locks for suitcases and the like. U.S. Pat. No. 3,875,771 describes an arrangement wherein a free end of the flexible fabric strap is passed through a hollow lock body from one end to the other and is secured therein by a resiliently biased toothed cam which is held in a locked position by tension on the strap. The strap is releasable from the lock by a key which disengages the toothed cam from the strap. U.S. Pat. No. 4,685,315 describes a lockable luggage strap which has a lever actuated cam member located within a hollow housing with a lockable cover to retain the cam lever in a locked position and otherwise prevent access thereto.
Neither of U.S. Pat. Nos. 3,875,771 or 4,685,315 would be suitable as a lockable tie down for surfboards or the like due to the difficulty of threading the free end of the strap through the locked body in an overhead position on a vehicular roof rack. Moreover, as both describe a simple fabric strap prone to stretching under prolonged tension during travel these straps would loosen sufficiently to allow a surfboard to be slid out from under the straps. Yet further disadvantages with these luggage straps is that they are easily cut with a knife and the strap engaging mechanisms would damage the straps leading to early failure.
U.S. Pat. Nos. 6,163,935 and 6327752 respectively describe tensionable locking clamps for tie down cables and tie down cords or straps. In both cases a free end of a cable, cord or strap has fixedly secured thereon a transverse retaining post engageable in spaced slotted apertures on the inner side of a hinged lid of a lockable hollow body to prevent disengagement of the retaining post. A plurality of spaced slotted apertures are provided to enable the hinged lid to function as a tensioning lever. The other end of the cable or cord is captively retained in the hollow body by a wedge mechanism which allows the length of the cable or cord to be adjusted when the hollow body is not under tension. The use of thin cables or cords is not recommended where a surfboard is to be secured to a roof rack by tensioning the cable or cord to achieve the required degree of frictional engagement as the point load applied by the narrow cord or cable can easily damage the surfboard.
A strap lock described in U.S. Pat. No. 6,510,717 is designed to secure a bicycle or the like to a bicycle rack or post-like structure such as a signpost or the like. The strap is reinforced to resist cutting and a cam locking device for the strap is located within a tamperproof hollow body secured by a lockable lid. The strap enters a slot at one end of the body, passes under the cam locking device and exits via another slot at the other end of the body. By passing straight through the body the strap cannot be tensioned efficiently by hand and as the cam lock is formed integrally with the hinged cover for the body, it actually loosens the strap as the cover is moved to the closed position. As with the luggage straps of U.S. Pat. Nos. 3,875,771 and 4,685,315, this device would be difficult to use in an overhead position in securing a surfboard to a roof rack.
U.S. Pat. No. 6,199,412 describes a lockable tie down strap for a variety of loads to be secured to a vehicle roof rack or the like. The device includes a steel reinforced strap to resist being cut with a knife but has an exposed captive end which is easily disengaged by cutting stitching between the strap and a free end thereof folded back upon itself after passing over a transverse retaining bar in a strap retaining mechanism. The strap retaining mechanism comprises a base, upright side members and a latch member forming a hollow housing locating the operative tongue portion of a lock mounted on the latch member. The tongue portion of the lock is accessible by a screwdriver or the like via an aperture in the rear of the body of the strap retaining mechanism. A further disadvantage is that a toothed self-locking jaw is located remotely from a pivotal mounting of the latch whereby release of the locking jaw is difficult and causes frictional wear on the strap when the toothed jaw is disengaged tangentially along a surface of the strap extending around a retaining pin.
While each of the aforementioned lockable securing devices is generally satisfactory for a respective intended purpose, none provide a simple yet elegant solution to the problem of easily and safely securing surfboards, snow boards and the like to vehicular supporting racks or frames.
It is an aim of the present invention to provide a lockable tie down strap for surfboards, snow boards and the like wherein at least some of the disadvantages of prior art securing devices are overcome or ameliorated.